mm/damon/tests/core-kunit: add damos_commit_filter test

Add unit test to verify that damos_commmit_filter() change dest value
well.

Link: https://lkml.kernel.org/r/20250817021348.570692-1-ekffu200098@gmail.com


Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>